Wireless communication systems are subject to unsmooth communications of a terminal and a base station because of a geographical condition in a cell, a distance between the terminal and the base station, or movement of the terminal.
To address this problem, the wireless communication system provides a small cell service to provide high speed data services to users within a macro cell. The wireless communication system, including the macro cell and the small cells, is configured as shown in FIG. 1.
FIG. 1 illustrates a conventional wireless communication system including a macro cell and small cells.
The wireless communication system of FIG. 1 includes a macro Base Station (BS) 100 managing the macro cell, and hot zone BSs 110 and 120 managing the small cells.
The hot zone BSs 110 and 120 use the same frequency band as the macro BS 100. The plurality of the adjacent hot zone BSs can be operated as a single hot zone BS group 120.
When the wireless communication system includes the macro cell and the small cells that use the same frequency band, a Mobile Station (MS) cannot maintain the connection to the macro BS within the small cell. Hence, the wireless communication system supports handover between the macro cell and the small cell to service the seamless communication to the MS. For example, the MS performs the handover as shown in FIG. 2.
FIG. 2 illustrates the handover of the MS in the conventional wireless communication system.
When the wireless communication system covers the macro cell and the small cells as shown in FIG. 2, the MS is handed-over to its cell. For example, when the MS 220 travels in the service coverage of the macro BS 200, the MS 220 is serviced by accessing the macro BS 200.
When the MS 220 migrates to the service coverage of the first hot zone BS 210, the MS 220 is handed-over to the first hot zone BS 210.
As discussed above, the wireless communication system, including the macro cell and the small cells, supports the handover between the macro cell and the small cells to offer the seamless communication to the terminal. The wireless communication system, including the macro cell and the small cells, confronts the frequent handovers of the MS, as compared with a wireless communication system including only the macro cell. Accordingly, the wireless communication system, including the macro cell and the small cells, suffers from the overhead increase according to the handover.